The adiposity of CRLM before targeted therapy initiation may serve as a marker to distinguish KRAS mutation status：A retrospective study

Abstract OBJECTIVE This study aimed to explore the correlation between MRI-related parameters and the Kirsten rat sarcoma viral oncogene (KRAS) gene mutation status in colorectal cancer liver metastases (CRLM) prior to initiating targeted therapy. METHODS This retrospective study enrolled 118 patients diagnosed with colorectal cancer liver metastases, each presenting up to three lesions of the largest diameter, and all underwent testing for KRAS gene mutations. Patients were categorized into two groups: the KRAS gene mutant (+) group (53 patients, 119 lesions) and the wild-type (-) group (65 patients, 155 lesions). Normality of continuous variables was assessed using the Kolmogorov-Smirnov test, while the Mann-Whitney U test or T test was employed for comparing continuous variables, and the Chi-square test for categorical variables. Variables exhibiting significant differences (p < 0.05) were subjected to multivariate logistic regression to identify independent factors and construct predictive models. Model performance was assessed through the receiver operating characteristic curve (ROC), with the area under the curve (AUC) and its 95% confidence interval (CI) calculated. RESULTS The T2-SI mean was higher in the KRAS(+) group compared to the KRAS(-) group (0.91 ± 0.30 vs 0.87 ± 0.39, p < 0.001). Conversely, T2FS-SI mean was significantly lower in the KRAS(+) group compared to the KRAS(-) group (0.80 ± 0.27 vs 1.02 ± 0.65, p < 0.001). Additionally, the proportion of lesions with a well-defined boundary was notably higher in the KRAS(+) group compared to the KRAS(-) group (84.9% vs 65.2%, p = 0.011). ROC curve analysis demonstrated that the model (Y = 0.890 + 0.878 * Boundary + 5.955 * T2-SI mean − 5.667 * T2FS-SI mean ) yielded an AUC value of 0.745 (95% CI: 0.688–0.802) for predicting the mutational status of the KRAS gene. CONCLUSION In our study, higher T2-SI mean , lower T2FS-SI mean and clear tumor boundaries in CRLM prior to initiating targeted therapy were associated with KRAS mutations.This implies that the adiposity of CRLM before targeted therapy initiation may serve as a marker to distinguish KRAS mutation status.